Recently, mobile computing devices are becoming smaller and offering more user features. A mobile internet device (MID), for example, is a multimedia-capable handheld computing device use in conjunction with wireless internet access.
Device manufacturers provide different user interfaces for application control on mobile devices. Such user interfaces usually require direct physical contact with the mobile devices. Examples of user interfaces include touch screens and on-device buttons. Typically, the user interfaces require use of two hands to operate which is not very convenient especially when a user is busy with another task or is handling one or more computing devices at the same time.
Moreover, user interfaces consume battery power to operate. If a user interface component is built-in with a portable device, the component consumes power from a battery of the portable device. This reduces the battery life of the portable device. On the other hand, for a user interface component that is standalone (detached from a portable device) and requires a battery to operate, the battery increases the weight and the size of the component itself. Additionally, users need to recharge or replace a battery so that the user interface component operates properly.